None.
The present invention relates to trailer hitches such as ball hitches supporting a trailer from the rear of a towing vehicle, and more particularly to retractable trailer hitches, which move between an extended position during use and a retracted position beneath a surface or bed of the vehicle when not in use for loading items into the bed without interference from the retractable hitch.
Hitch balls and ball hitches of the prior art for gooseneck type trailers are usually bolted, permanently mounted, or welded to the bed of pickup trucks or similar vehicles. If the hitch ball is in the upright position above the surface of the pickup bed, it is difficult to lay large items flat on the floor of the pickup bed, which creates potential damage to other cargo or renders one third or more of the flattened floor space unusable. Furthermore, the hitch ball can be hazardous to mobility within the pickup bed.
Various types of retractable hitches exist in the past. For instance, U.S. Pat. Nos. 3,385,611, 4,256,324, 4,540,194, 4,570,966, 4,657,274, 5,755,452, 5,860,671, 5,893,575 and 5,906,387 all disclose various types of retractable hitches.
Retractable hitches have numerous desired operational characteristics. In general, retractable trailer hitches have to be strong to support the vertical weight (or, depending upon loading, in some instances lift) of the trailer tongue, as well as the horizontal drag or towing force for the trailer. Retractable hitches should be made reliable to work on a consistent basis. Operational control between a retracted position and an extended position should be as simple as possible, but should also be as xe2x80x9cfail-safexe2x80x9d as possible to prevent inadvertent or unwanted retraction. The operation must also be robust so as to work over an extended period of time despite the often hazardous, dirty or corrosive conditions that trailer hitches may be subjected to over years of use. Repair of such trailer hitches should also be made simple and efficient. The present invention seeks to fulfill all of these various desired operational characteristics, without many of the drawbacks of prior art retractable trailer hitches.
The present invention involves a retractable hitch adapted to be mounted to a vehicle, such as in the bed of a pickup truck. The hitch includes a ball piece for releasable engagement with a coupling mechanism secured to a trailer as known in the art. The hitch has a frame secured to the vehicle, and the frame provides a substantially flat upper surface with an opening extending below the upper surface. The ball piece moves between an operative position, wherein it extends above the upper surface, and a retracted position wherein the ball piece is positioned below the upper surface. A raising/lowering control moves the ball piece between the operative position and the retracted position. The raising/lowering control is mechanically coupled to the ball piece through a raising/lowering control linkage. The raising/lowering control linkage is positioned so as to allow substantially unimpeded access to the ball piece in the operative position for the engaged coupling mechanism on the trailer. In one aspect, operation of the raising/lowering control linkage involves only translational movement which can be quickly accomplished. A locking control is used for selectively locking the ball piece in the operative position. The locking control is mechanically coupled to the ball piece through a locking control linkage positioned so as to allow substantially unimpeded access to the ball piece in the operative position for the engaged coupling mechanism on the trailer.